Conventional levels typically have an elongated body with a reference surface, and one or more level vials, also known as spirit vials or bubble vials, inserted therein and calibrated with respect to the reference surface, so that a bubble floating on the liquid within the level vial aligns within a demarcated region of the level vial when the reference surface is itself level (e.g., when it is placed against a level surface), but floats out of the demarcated region when the reference surface is not level (e.g., when the reference surface is placed against a surface that is not itself level). Many conventional levels include a top vial which extends along the top of the level, parallel to the reference surface, and a pair of side vials that are supported in the sides of the level, and are visible from opposing faces of the level. Such side vials typically are oriented as plumb vials, perpendicular to and/or at a 45° angle relative to the reference surface.
Conventionally for such side vials, the vial liquid housing is formed as a tube that is subsequently assembled into a clear annular housing that surrounds the vial liquid housing on both sides, and allows the vial liquid housing to be supported in the level housing in a manner that is visible from opposing faces of the level. Typically the clear annular housing is formed as two halves, which are assembled together surrounding the vial liquid housing. In other conventional side vials, a block containing the vial liquid housing is formed integrally into a generally cylindrical housing body, where the housing body again forms opposing transparent circular disks supporting the block vial in between. It may be appreciated that in each of these conventional vial housings, having a generally cylindrical overall configuration designed for viewing from opposing sides, a transparent housing surface of the clear housing body is positioned between the vial liquid housing and a user of the level. While such clear housings provide adequate support for the vial liquid housings therein, it is understood that such transparent housing surfaces may become scratched or smudged, and may obscure magnification properties based on the curved configuration of the vial liquid housing supported within the clear housing bodies.